1. Field of the Invention
The present invention relates to a facade system with a translucent porous insulating material of mineral or organic fibers; the insulating material having on the outside a colored layer for controlling light transmittance and improving appearance.
2. Description of the Related Art
A generically determinative facade system is known from EP 0 362 242. This known facade surfacing has an insulating layer of heat-insulating material with light-admitting weatherproofing provided on the outside in the form of a transparent outer covering, produced for example from silicate glass or synthetic glass. The insulating layer, which may be produced, for example, from a multiplicity of factory-prefabricated glass-fiber or mineral-fiber insulating boards which are fastened on the outer wall of the building adjacently in a surface-covering manner, is designed in such a way that a temperature profile can be adjusted, when there is usable solar irradiation, with a maximum value within the insulating layer. For this purpose, the insulating layer can be designed to be opaque or translucent between its outer and inner bounding surfaces, with a transmittance xcfx84 of less than 10% and an absorbance a of more than 15%.
The innovative facade surfacing has proved to be entirely serviceable, but has the disadvantage that, with the outer covering with which it is provided, designed as a transparent layer and made, for example, of silicate glass, synthetic glass or weatherproof sheetings, it is not possible to achieve building facades which are visually and/or aesthetically pleasing for the house owner or viewer. This is true because in the case of such a configuration of the known facade system the outer or viewer-side surface of the insulating layer, which lies behind the transparent weatherproofing layer or outer covering and the surface structure can be clearly seen. This does not lend a building facade with a pleasing exterior appearance. Although it has already been proposed in EP 0 362 242 to tint the outer covering by coloring the panels forming it, this is very costly and is not possible in any desired color. Alternatively, it has been proposed in EP 0 362 242 to color or pattern the outer surface of the insulating layer or provide it with motifs. Quite apart from the fact that this proposal has not proved to be feasible in practice, coloring the outer insulating layer does not in any way have the effect of lending its surface a different appearance than that which is predetermined by the structure or position of the fibers forming the insulating layer. As already stated above, the latter is, however, not satisfactory from a visual and/or aesthetic viewpoint.
A further problem is the appearance of the region where the insulating boards are joined. Here there is the great risk that, in particular, with a dark outer surface of the insulating layer, if the insulating boards are not laid in line or accurately, the mineral wool lying behind, which for example is lighter, becomes visible and can be seen as a light line. This additionally has an adverse effect on the overall appearance of the facade.
This gives rise to the object of the present invention of further developing the generic facade system in such a way that an appearance which is visually and/or aesthetically satisfactory or pleasing to the viewer can be produced.
This object is achieved by the present invention, which provides a facade system with a translucent porous insulating material of mineral or organic fibers for passive solar energy utilization, wherein the insulating material has on the outside a colored layer (2,2xe2x80x2) for controlling the light transmittance xcfx84 and improving the appearance.
The fact that the insulating material or the insulating layer of the facade system according to the invention is for the first time provided with a colored layer on the outside allows the unsightly surface structure of the insulating layer to be replaced by a visually and/or aesthetically pleasing surface structure which, moreover, can be provided with any desired tinting. This advantageously makes it possible, in addition, to use this externally applied colored layer for design purposes in any form and at the same time specifically control the light transmittance xcfx84 with this colored layer.
Another embodiment of the present invention provides a facade system whereby controlling of the light transmittance xcfx84 can take place by means of a different color graduation of the colored layer. Consequently, allowance can be advantageously made for different angles of incident light radiation and radiation intensities by appropriate tinting. This makes it possible for the first time to control the light transmittance xcfx84 by increased light reflection or light absorption a.
The light reflection or absorption of the colored layer can be advantageously controlled by a suitable pigmentation of the respectively chosen color or by the incorporation of metal particles in the colored layer. This opens up a wide range of possible variations with regard to the surface design of the colored layer, the choice of color and color intensity and also the controlling of the light transmittance xcfx84 in every respect.
A particularly low-cost alternative embodiment is the laminating of a colored glass-fiber felt onto the insulating material in order to apply the colored layer according to the invention. The colored layer or the colored glass-fiber felt may, for example, be adhesively attached to the insulating layer or be applied in some other way. In the case of adhesive attachment, a foam adhesive which has been specially developed for this purpose has proven to be particularly advantageous. This foam adhesive is described in German Patent Application DE 197 46 442.4 by the same applicant, the complete disclosure of which is fully incorporated herein by reference. This special foam adhesive does not show through the felt to be adhesively attached when it is applied. This is in contrast to the possibility that a conventional full-surface adhesive may show through the felt and, as a result, spoil the uniform coloration or color appearance.
It is at the same time also an advantage of the present invention that the colored layer can for the first time be of a color-fast design with respect to UV irradiation. What is more, in the case of a further embodiment, a clear cost reduction is evident if a glass panel, in particular a commercially available glass panel, is provided as the transparent weatherproofing or transparent outer covering, since tinted types of glass are more expensive than clear types of glass. For the visual and/or aesthetic design of the facade to be further optimized, there may additionally be the case in the facade system according to the invention that the glass panel itself is provided with a pattern, in particular with a grid-shaped or symbolic pattern.
The fact that the light transmittance xcfx84 is for the first type controlled by means of the colored layer makes it possible to ensure in an aesthetically pleasing way that in the summer there is no overheating of the building wall adjoining the facade system. This takes place in a particularly advantageous way by the insulating layer with the colored layer being designed such that a temperature profile can be achieved, when there is usable solar irradiation, with a maximum value within the insulating layer, a light transmittance xcfx84 of less than 10% being set between its outer and inner bounding surfaces.
The facade system can be constructed in a quick and efficient way, by applying the insulating layer and the colored layer together in the form of factory-prefabricated facade insulating boards. When doing so, the colored layer preferably protrudes beyond the insulating layer along two board edges.
In a particularly advantageous embodiment, the colored layer is designed in such a way that, for example along two angularly neighboring board edges, it protrudes beyond the latter. Consequently, when the facade insulating boards are applied to the building wall, the abutting edges in the region of the joins between neighboring insulating boards are covered by the overlapping protruding colored layer. Consequently, the occurrence of differently colored or light lines is eliminated and the overall appearance of the facade is not adversely affected if, for example, the joins of the facade insulating boards are not in line, since the joins between the insulating boards are covered by the overlap and are consequently not visible. A facade with the appearance of uniformity of the desired color is the result.
In a further advantageous embodiment, the colored layer is applied to the prefabricated facade insulating board in such a way that, similar to the lamination of an edge strip mat, the colored layer protrudes parallel to and along two opposite board edges beyond the latter. Consequently, abutting edges in the region of the join between neighbouring insulating boards are likewise covered by the overlapping protruding colored layer, which presupposes, however, that the individual facade insulating board is of a square design and, when being applied to the building wall can be turned alternately through 90xc2x0, so that, in a way analogous to the imbricated overlapping explained above, complete coverage of all the joins is likewise achieved. What is more, a square form with parallel projections makes it possible for the facade insulating boards to be produced at low cost, since, starting with an initially endless mineral wool web, the latter can be continuously laminated with the colored felt directly on the line and subsequently divided into the finished facade insulating boards.
A further advantage is that, in the case of the facade insulating board according to the invention, with a transparent or translucent colored layer for improving the visual appearance of the joins, it is not required for a felt strip to be stuck over the joins at the site.